using System;

public class Program

{

    public static void Main()

    {

        Random rnd = new Random();

        int rndNumber = rnd.Next(1,20);

        int userNumber = 0;

        int userGuess = 0;

        bool guess = false;

        bool valid = false;

        while (guess != true) {

            while (valid != true)

            {

                Console.WriteLine("Please enter a number between 1 and 20");

                userNumber = Convert.ToInt32(Console.ReadLine());

                if (userNumber > 20)

                {

                    Console.WriteLine("Your number is to high. Your number should be below 21");

                }

                else if (userNumber < 0)

                {

                    Console.WriteLine("Your number is to low. Your number should be above 0");

                }

                else

                {

                    valid = true;

                }

            }

            userGuess = userNumber;

            if (userGuess > rndNumber)

            {

                Console.WriteLine("Your guess is to high. Guess Lower");

            }

            else if (userGuess < rndNumber)

            {

                Console.WriteLine("Your guess is to low. Guess Higher");

            }

            else 

            {

                guess = true;

            }

        }

        Console.WriteLine("You guessed correct! My number is " + rndNumber);

    }

}